Method of making a headliner having integrated energy absorbing foam

ABSTRACT

A method of manufacturing a headliner assembly for use in the interior compartment of an automotive vehicle comprising the steps of: placing a mold release film onto a concave mold surface of a lower mold assembly for providing a barrier against the mold surface; placing a fiber mat on the mold release film; applying a foamable material directly onto the fiber mat; expanding the foamable material around the fiber mat to embed the fiber mat therein; placing an adhesive film onto a convex mold surface of an upper mold assembly; positioning the lower mold assembly directly beneath the upper mold assembly; moving the upper mold assembly in mating engagement with the lower mold assembly to define a mold cavity between the convex mold surface and concave mold surface; curing the foamable material within the mold cavity; and bonding the mold release film and adhesive film to the foamable material with the fiber mat embedded therebetween. A layer of scrim is then adhered to the mold release film and a layer of fabric is adhered to the adhesive film for providing a decorative cover to the headliner assembly.

This application claims the benefit of provisional application No.60/159,418, filled Oct. 14, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention generally relates to a headliner assembly and amethod and apparatus for manufacturing a headliner assembly of anautomotive vehicle. More specifically, the invention relates to a methodand apparatus for manufacturing a headliner assembly having integratedenergy absorbing foam.

2. Description of the Related Art

Automotive vehicle headliner assemblies are used to line the ceiling orunderside of the roof within the interior compartment of the vehicle.The headliner assembly typically includes a fabric layer that provides adecorative cover to the ceiling, a soft flexible foam intermediate layerof a relatively thin configuration, a layer of imperforate urethane filmlaminate disposed on the surface of the soft foam intermediate layeropposite the fabric layer, and a thick, rigid polyurethane foam layerformed on the imperforate film as the innermost layer of the headlinerassembly.

It is also known to manufacture headliner assemblies having varyingthicknesses of urethane foam for providing enhance strengthcharacteristics and acoustical effects. For example, U.S. Pat. No.5,683,796 discloses a method of making a headliner assembly having anexterior surface of a fabric layer providing a decorative cover and abody of foamed material adhered to the opposite interior surface of thefabric layer having central portions with a greater thickness thanperipheral portions thereof. The body of foamed material has a constantdensity throughout its extent including the central and peripheralportion to provide desired strength, weight and acoustic characteristicsto the overall headliner assembly. However, the headliner assembly ofthis type does not adequately address desired energy absorptioncharacteristics or rigidity for use in mating engagement with the roofof the vehicle.

Therefore, it is desirable to manufacture a headliner assembly havingcontoured portions of varying foam thickness and density by embedding afiber mat within a layer of urethane foam forming a rigid and integratedenergy absorbing headliner assembly.

SUMMARY OF THE INVENTION

The present invention relates to a method of manufacturing a headlinerassembly for use in the interior compartment of an automotive vehiclecomprising the steps of: placing a mold release film onto a concave moldsurface of a lower mold assembly for providing a barrier against themold surface; placing a fiber mat on the mold release film; applying afoamable material directly onto the fiber mat; expanding the foamablematerial around the fiber mat to embed the fiber mat therein; placing anadhesive film onto a convex mold surface of an upper mold assembly;positioning the lower mold assembly directly beneath the upper moldassembly; moving the upper mold assembly in mating engagement with thelower mold assembly to define a mold cavity between the convex moldsurface and concave mold surface; curing the foamable material withinthe mold cavity; and bonding the mold release film and adhesive film tothe foamable material with the fiber mat embedded therebetween. Thelayer of scrim is then adhered to the mold release film and a layer offabric is adhered to the adhesive film for providing a decorative coverto the headliner assembly.

The present invention also relates to a molding apparatus formanufacturing a headliner assembly for. use in the interior compartmentof an automotive vehicle comprising a support frame. An upper moldassembly is supported by the support frame for vertical movement andincludes a convex mold surface. A lower mold assembly is supported bythe support frame beneath the upper mold assembly and includes a concavemold surface. The upper mold assembly is movable into mating engagementwith the lower mold assembly to define a mold cavity formed between theconvex mold surface and the concave mold surface for manufacturing theheadliner assembly therein.

The headliner assembly comprises a fiberglass mat embedded within alayer of urethane foam forming a contoured substrate having opposingfirst and second sides. A mold release film is affixed to the first sideand an adhesive film is affixed to the second opposing side. A layer ofscrim is adhered to the mold release film for providing resiliency andsound absorption to the headliner assembly. A layer of fabric is adheredto the adhesive film for providing a decorative cover to the headlinerassembly wherein the headliner assembly is formed of a predeterminedcontour having areas of various thickness of the urethane foam forproviding integrated energy absorption in the headliner assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswherein:

FIG. 1 is a schematic side view showing a molding apparatus utilized inmanufacturing the headliner assembly in accordance with the principlesof the present invention;

FIG. 2 is a partial schematic side view showing the start position ofthe molding method and apparatus;

FIG. 3 is an top view of the portion of the molding apparatus shown inFIG. 2;

FIG. 4 is schematic side view showing the molding apparatus with theupper and lower mold assemblies in mating engagement for molding aheadliner assembly;

FIG. 5 is a sectional view taken along line 5—5 of FIG. 4;

FIG. 6 is a partially exploded view of the headliner assembly showingthe different layers of the headliner assembly in accordance with theprinciples of the present invention;

FIG. 7 is a side view showing the contour of the headliner assembly;

FIG. 8 is an enlarged view of the energy absorbing contour in the area Aof FIG. 7; and

FIG. 9 is a side view of the headliner assembly showing sound absorbingapertures disposed therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a schematic side viewof a molding apparatus 10 used for manufacturing a headliner assembly inaccordance with the principles of the present invention is generallyshown in FIG. 1. The molding apparatus 10 includes a rigid support frame12 for supporting an upper mold assembly 14 for vertical movement. Theupper mold assembly 14 has a convex mold surface 16 which is shaped inconformance with the desired uppermost configuration for the headlinerassembly. The vertical movement of the upper mold assembly 14 can beaccomplished by any conventional means. In the preferred embodiment ofFIG. 1, the apparatus 10 includes a pair of die press columns 18 coupledto the frame 12 and extending between the upper mold assembly 14 and adie press 20. The die press 20 actuates the die press columns 18 and theupper mold assembly 14 for movement vertically with respect to the frame12. An encoder 22 determines and controls the relative position of theupper mold assembly 14.

The molding apparatus 10 further includes a fixed lower track assembly24 which extends through the frame 12 beneath the upper mold assembly14. A lower mold assembly 26 is mounted for horizontal movement on thetrack assembly 24 by bearings or wheel members 28. In FIG. 1, the lowermold assembly 26 is shown in its initial start position. The lower moldassembly 26 is movable along the track assembly 24 between the startposition and a mold position under the upper mold assembly 14 forcooperation therewith, as shown in FIG. 3. The lower mold assembly 26includes a concave mold surface 30 which is shaped in conformance withthe desired lowermost configuration for the headliner assembly. A pairof spray heads 32, 34 are mounted on the frame 12, above the lower moldassembly 26 in the start position, for transverse movement with respectto the lower mold assembly 26. The spray heads 32, 34 are connected to asource of foamable material, such as liquid urethane, as designated at36. A pair of spray heads 32, 34 are provided in order to reduce theamount of time to apply the liquid foamable material during themanufacturing process.

Referring to FIG. 2, the spray heads 32, 34 are spaced apart and fixedlymounted on a carriage assembly 36 which is mounted for movement on anupper track assembly 38 fixed to the frame 12 and suspended above thelower mold assembly 26. That is, the track assembly 38 suspends thespray heads 32, 34 and carriage assembly 36 above the lower moldassembly 26 in the start position for application of the liquid foamablematerial. The upper track assembly 38 includes a pair of parallel trackmembers 40, 42 extending transverse, or substantially perpendicular, tothe lower track assembly 24 therebeneath. A pair of spray head mountingmembers 44, 46 are each slidably mounted on a respective track member40, 42, such as by a bearing coupling. The carriage assembly 36 includesa connecting drive nut 48 having internal threads which cooperate withexternal threads of a drive screw 50. The drive screw 50 is mounted forrotation on the upper track assembly 38 and extends in parallel relationbetween the track members 40, 42. The drive screw 50 is rotated at oneend by a bi-directional electric motor 52 to effect transverse movementof the carriage assembly 36, and spray heads 32, 34, on the trackassembly 38. The opposite end of the drive screw 50 is rotatable mountedin a bearing coupling 54 on the track assembly 38. The bi-directionalmotor 52 is adapted to alternately rotate the drive screw 50 in oppositedirections to effectuate fore and aft movement of the carriage assembly36 along the upper track assembly 38. The direction and speed of themotor 52 may be controlled by a controller, or computer.

Referring to FIG. 3, the first step on the method of manufacturing aheadliner assembly in accordance with the present invention includesplacing a mold release film 60 onto the concave mold surface 30 of thelower mold assembly 26 in the start position. The film 60 may be held onthe concave mold surface 30 by clamps, fasteners, or vacuum pressure.The film 60 provides a barrier to the mold surface 30 from the liquidurethane 64. A fiberglass mat 62 is then laid onto the mold release film60. The fiberglass mat 62 may by any type of fibrous mat includingnatural fiber. The positioning of the mold release film 60 andfiberglass mat 62 is typically done manually, however, the method mayinclude automated placement of the layer of the film 60 and mat 62 ontothe mold surface 30. The next step includes the spray heads 32, 34applying a spray of liquid foamable material 64, preferably liquidpolyurethane, to form a polyurethane foam layer around the mat 62 overthe entire area of the concave mold surface 30. After the liquidurethane is sprayed onto the mat 62 it begins to crosslink and expandaround the mat 62 so that the mat 62 is enclosed within the urethane. Ahigher volume of urethane is sprayed on area of the mat 62 for forming agreater thickness to portions of the headliner as will be furtherdiscussed hereinbelow. Either before, during or after the urethane issprayed onto the mat 62, an adhesive film 66 is attached over the convexmold surface 16 of the upper mold assembly 14, as shown in FIG. 1. Theadhesive film 66 may be secured to the upper mold assembly 14 over theconvex mold surface 16 by clamps, fasteners or vacuum pressure.

Shortly after the liquid urethane is sprayed onto the mat 62, or evenduring the spraying, the lower mold assembly 26 is rolled along thelower track assembly 24 beneath the upper mold assembly 14. The diepress 20 is then actuated to move the die press columns 18 downwardlyand lower the upper mold assembly 14 into mating engagement with thelower mold assembly 26 as shown in FIG. 4. A cavity is formed by themating engagement of the upper 14 and lower 26 mold assemblies betweenthe convex mold surface 16 and the concave mold surface 30. The molds14, 26 remain in mating engagement while the urethane continues toexpand and fills the cavity between the mold surfaces 16, 30. Thecavity, defined by the convex and concave shape of the respective moldsurfaces 16, 30, forms the shape of the headliner with dimensions asspecified by a particular vehicle design. Additionally, heat and/orpressure may be applied to the upper 14 and/or lower 26 mold assembliesto increase the rate of expansion and formation of the urethane asdesired.

The urethane eventually cures and bonds to the mold release film 60 andadhesive film 66 forming a urethane substrate 68 with the fiberglass mat62 embedded within the urethane 64, as shown in FIG. 5. Referring toFIG. 6, subsequent to the forming of the urethane substrate 68, a layerof fabric 70 is applied to, or laid over, the adhesive film 66. Heat isapplied to activate the adhesive film 66 for bonding the fabric 70 tothe substrate 68. The fabric 70 comprises a layer of woven or non-wovenmaterial, such as cloth, vinyl, or leather, which may be foam backed forproviding a decorative cover to the interior passenger compartment ofthe vehicle.

A layer of scrim 72 is also applied to, or laid over, the mold releasefilm 60 and bonded thereto with web adhesive or an equivalent as isknown to one skilled in the art. The scrim 72 comprises a layer ofcotton fiber, synthetic fiber, or foam as is known to one skilled in theart, for preventing squeaking noise with the roof of the vehicle whenattached thereto. Alternatively, the mold release film 60 may be alaminate of film 60 and scrim 72. Still further, the mold release film60 and/or adhesive film 66 may be a prelaminated combo mat including thefilm 60, 66, scrim 72 and chopped glass.

Referring to FIG. 6, a partially exploded view of a headliner is shownat 80 as constructed according to the above described method. Thefiberglass mat 62 is shown surrounded by, embedded and suspended withinthe urethane foam 64 forming the urethane substrate 68 to enhance thestrength characteristics of the headliner 80. The mold release film 60is attached to one side of the substrate 68 and the adhesive film 66 isattached to the other side of the substrate 68. The fabric 70 is adheredto the adhesive film 66 and the scrim 72 is adhered to the mold releasefilm 60.

The thickness of the substrate 68 is inversely proportional to thedensity of the urethane. Although the amount of liquid urethane 64applied to the mat 62 can be adjusted according to desired designthickness of the headliner 80, the narrower cross-section of thesubstrate 68 will still have higher density than the thickercross-sections due to the expansion properties of the urethane 64.

The exterior dimensions of the headliner 80 and overhead component holesmay be cut with a water jet (not shown), however, other conventionalmethods of cutting such as with a piercing tool will suffice. When edgewrapping of the headliner 80 with the fabric 70 is desired, a pre-cut ofthe exterior dimensions are made to the substrate 68 prior to applyingthe fabric 70. A second cut is made of the fabric 70 leaving enoughexcess fabric to edge wrap as is known in the art of headlinermanufacturing.

The cross-section of an example contour for the headliner 80 is shown inFIG. 7.

An alternative method of manufacturing does not require that the lowermold 26 be mobile which allows for the elimination of the lower moldwheels 28. Therefore, the lower mold 26 is stationary beneath the uppermold 14. For the alternative method, the liquid urethane 64 is appliedto the mold release film 60 and mat 62 which rests on a flat surface anda wet composite is subsequently slid onto the lower mold 26 whilebeneath the upper mold 14. The upper mold 14 is actuated into matingengagement with the lower mold 26 by the die press 20 for forming thesubstrate 68 and the process is continued according to the prior methodstated hereinabove.

The method for manufacturing the headliner 80 provides design benefitsfor the headliner not available to prior art manufacturing methods. Forexample, devices, such as foam blocks, sinusoidal plastic inserts, ribcartridges and wire cages are glued to upper surfaces of headliners forabsorbing head impact energy. The addition of these devices addsassembly time and significant cost to the price of a headliner assembly.The subject manufacturing method provides the ability to add head impactcontours as shown at 82 into the urethane substrate 68 as is representedin FIG. 7. The addition of these contours 82 does not add cost andassembly time to the headliner manufacturing process. The contour andthickness of the urethane substrate 68 can be modified to optimizeenergy absorption by simply designing the tool cavity accordingly. Forexample, it is known to those of skill in the art of energy absorptionthat sinusoidal contours in energy absorbing components provide moreenergy absorption than does a smooth contour. Sinusoidal contours can bedesigned into the mold cavity providing the desired energy absorptionproperties to the headliner assembly without adding additionalcomponents to the assembly. A sinusoidal contour 84 is represented bestin FIG. 8. Alternate contours such as, for example, a pattern ofcavities in the substrate 68 is also known to be effective both formolding and for energy absorption. Alternatively, energy absorbingdevices can be inserted into the mold cavity prior to the liquidurethane wherein the urethane will expand around the device securing itonto the substrate 68. This eliminates the step of gluing the device tothe substrate 68.

The thickness of the urethane substrate 68 is known to be directlyproportional to the overall strength of the headliner 80. An increase inthickness of the headliner 80 provides efficiency benefits to vehiclemanufacturing derived from the strength of the headliner 80. Forexample, modern vehicle manufacturing utilizes modular subassembliessuch as a headliner assembly having all of the overhead components (i.e.sun visors, assist grips, coat hooks) attached prior to being installedinto a vehicle. Current headliner substrate technology, such astramivex, dry polyurethane and fiberglass is not able to support theseoverhead components during a modular build operation without crackingand breaking. The urethane substrate 68 of the subject concept can bethickened either locally, or generally, providing the strength as neededfor supporting the modular build components.

The thickness of the urethane substrate 68 can also be optimized forproviding structural support to a vehicle roof. For example, gluing theupper surface 86 of the headliner 80 to an underside of a vehicle roofwith hot melt glue or an equivalent provides enough structural supportto the roof to eliminate structural roof bows. The elimination of thestructural roof bows increases vehicle interior space, reduces vehiclemass, and reduces vehicle cost. Utilizing the subject headliner 80 forstructural support prevents deflection of the vehicle roof while under aload of up to several hundred pounds.

To meet vehicle interior acoustic standards, the urethane substrate 14may include a plurality of apertures 88 pierced into the lower surface90 as shown in FIG. 9. The apertures 88 deflect sound wavesreverberating inside the vehicle interior for reducing the overall soundlevel therein. The fabric 70 overlays the apertures 88 for preventingthe apertures 88 from being visible to the vehicle occupants. A piercingstep prior to affixing the fabric 70 to the urethane substrate 68 isadded to the headliner manufacturing process for inserting the apertures88. However, other methods for adding the apertures 88 are contemplatedsuch as, for example adding pins to the surface of one or both of theupper and lower mold 14,26.

The method for manufacturing the headliner 80 explained hereinabovefurther provides the ability of inserting the overhead components suchas assist grips, wiring harnesses, lighting components, and coat hooksinto the mold cavity thereby integrating the components into theurethane substrate 68. This further reduces the complexity of theassembly process and enhances the fit of the components to the headliner80 by form fitting the substrate 68 to the components when the urethaneexpands around the components.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation. Manymodifications and variations of the present invention are possible inlight of the above teachings. It is, therefore, to be understood thatthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A method of manufacturing a headliner assemblyfor use in the interior compartment of an automotive vehicle comprisingthe steps of: placing a mold release film onto a concave mold surface ofa lower mold assembly for providing a barrier against the mold surface;placing a fiber mat on the mold release film; applying a foamablematerial directly onto the fiber mat; expanding the foamable materialaround the fiber mat to embed the fiber mat therein; placing an adhesivefilm onto a convex mold surface of an upper mold assembly; positioningthe lower mold assembly directly beneath the upper mold assembly; movingthe upper mold assembly in mating engagement with the lower moldassembly to define a mold cavity between the convex mold surface andconcave mold surface; curing the foamable material within the moldcavity; and bonding the mold release film and adhesive film to thefoamable material with the fiber mat embedded therebetween.
 2. A methodas set forth in claim 1 further including the step of placing a layer offabric over the adhesive film and affixing the layer of fabric to theadhesive film for providing a decorative cover for the headlinerassembly.
 3. A method as set forth in claim 2 further including the stepof placing a layer of scrim over the mold release film and affixing thelayer of scrim to the mold release film for providing a noise and energyabsorption to the headliner assembly.
 4. A method as set forth in claim3 further including the step of forming a plurality of apertures in thefoamable material for absorbing noise in the headliner assembly.
 5. Amethod as set forth in claim 4 further including the step of coveringthe apertures with the layer of fabric.
 6. A method as set forth inclaim 5 further including the step of forming varying thicknesses anddensities of foamable material between the mold release film and theadhesive film to define contours for absorbing energy in the headlinerassembly.